Newly introduced legislation in Minnesota requiring labeling on all genetically engineered foods could set up a battle similar to the one waged in California over Proposition 37.

Minnesota could become the next battleground in the fight over mandatory labels for genetically modified food.

Bills were introduced Thursday in the Minnesota Legislature that would require food manufacturers to label their products to indicate whether they contain genetically engineered (GE) ingredients. Similar bills are being considered in other states, and California voters took part in a bruising battle last fall over the labeling issue.

The majority of packaged food in U.S. supermarkets is derived from genetically engineered crops like corn or sugar beets. Labeling proponents say the long-term health implications of GE crops are not known, and that consumers should have the right to know if the stuff is in their food.

The food industry, which has a big presence in Minnesota, says GE technology is supported by ample science and the approval of health and food regulators nationwide. Labels would be expensive and needlessly scare consumers, the industry maintains.

Karen Clark, DFL-Minneapolis, introduced a GE labeling bill in the Minnesota House and John Marty, DFL-Roseville, did the same in the Senate. The legislation would require the phrase "Produced with Genetic Engineering" on foods containing GE ingredients.

"I think everybody should know these ingredients are in the food they buy so they can make better choices," said Nancy Brown, coordinator of Right to Know Minnesota, which favors the labeling requirement.

Brown said she's "basically a concerned mother" who was surprised that GE ingredients were prevalent in food.

A spokesman for Gov. Mark Dayton said he hasn't reviewed the proposed legislation, referring any comment to the state's Department of Agriculture. It declined to comment.

If the bills get traction in the Legislature, it could make for a "very interesting square-off," said Mark Kastel, co-founder of the Cornucopia Institute, a Wisconsin-based organic food watchdog and labeling proponent. "In Minnesota, you have a very strong constituency of people who are 'food aware,'?" Kastel said.

The Twin Cities has a high concentration of retail food co-ops, which are often notably health-conscious. Plus, Minnesota is a strong market for organic products, Kastel said.

On the other hand, "you have some very large and powerful agribusiness companies headquartered there."

Golden Valley-based General Mills Inc., one of the nation's biggest packaged-food companies, spent $1.23 million last year to defeat Proposition 37, the California referendum to require GE labeling. That's according to MapLight, a nonpartisan research outfit, which said Austin-based Hormel Foods Corp. was next among Minnesota companies, spending $467,900.

Polls showed that voters in California initially favored Proposition 37 and GE labeling, but turned against it as food and agriculture industry opposition -- led by Monsanto -- mounted. The industry raised about $46 million to fight Proposition 37, five times as much as pro-labeling forces.

General Mills said Thursday that while it has not reviewed the Minnesota bills, the company and the entire industry have long opposed state-by-state labeling laws.

In a January interview with the Star Tribune, General Mills CEO Ken Powell reiterated that stance, saying "We strongly disagree with state-by-state labeling. ... If you can imagine 50 different states with 50 different labeling requirements -- I mean people are going to be paying a lot for food."

Doug Peterson, head of the Minnesota Farmers Union, said his organization supports GE labeling on a federal level, though not state-by-state. "Consumers want to know what's in the food they buy, and some people want to know if it's got [GE ingredients]," he said.